OK, so this should be labelled with extreme hazard warnings or something. A crazy laser enthusiast actually built his own lightsabre capable of burning straight through things.

The monster 3W laser, made from a diode taken out of a DLP projector bolted to two high-power lithium ion laptop batteries, is capable of burning straight through paper, cardboard, wood, and even a ping pong ball. You certainly wouldn't want this bad boy pointed in your direction.

Not quite a real flesh-and-blood lightsabre, but about as close as we're ever really going to get. Just don't get this thing anywhere near your eyes. [YouTube via TNW]